Process of coating and treating materials having an iron base



. L. HERMAN PROCESS 0F coATlNG AND TREATING MATERIALS HAVING AN IRONBASE.

APPLICATION FILED MAR. 6, 1922- ?atented 001:. 3, 1922.,

Innenma JOSEPH L. HERMAN, TEORIA, ELLINOIS.

PROCESS OF CQATING- AN D TREATING- MATERIALS HAVING AN TRON BAS. I

Application letl March 6, 1922. Serial No. 541,563.

To all whom t mayconoem:

Be it known that I, JOSEPH L. HERMAN, a citizen of the United States, aresident of Peoria, in the county of Peoria and State. of Illinois, haveinvented new and useful Tmprovements .in Processes of Coating andTreating Materials Having an Tron Base, of which the following is aspecification.

This invention has reference to a process of coating and treatingmaterials having an iron base, and particularly the coating andtreatment of wire used in the fence industry rand for telephone andother purposes.

' The principal object of this invention is to subject the material toan annealing process and then without allowing 4the annealed material tocome into contact with air subjecting the same to -a coating bath andfinally subjecting the coated material to a heat-treatment.

y Such heat-treatment has for its object an improved coating which will.be more resistant to atmospheric, 'rusting and corroding conditions thanis ordinary galvanized wire, and which further will permit a heaviercoated wire to be used in wire fabricating'machines, without causing thecoating to crack `or ake off asin the case with heavily lcoatedgalvanized wire Coated by ordinary processes; the. annealing of thematerial being for the usual softening purposes. c

A further object of the invention is to permit the use of higher speedsfor galvanizingwire than can be used under the'ordinary galvanizingprocesses where heavier coatings are desired and at the same timecausing a heavier coating to be formed on the wire.

This application is a companion to applications for patent filedby me ofeven date herewith bearing Serial Nos. 541,561 and l541,562 and theapplication for patent filed by me on February 10, 1922, bearing SerialNumber 535,660, 'all directed towards processes for coating and treatingmaterials having an iron base. The invention herein described diifersfrom those disclosedinsald pending applications, in that the material isannealed and then coated without allow'- ing said material to come intocontact with air. A

Galvanized wire which is lto be used for fabricating purposes andmoreparticularly that which is tobe used in the manufacture of woven wirefencing must have a'relativel i vbe a le to withstand atmosphericcorroding conditions, and before my invention was developed this was notpossible exceptfat a much increased cost of roduotion.v

The universal practice for testing the relative value of spelter ongalvanized wire, is by the so-called Preece or copper sulfate test.There are other tests, however, which are used for quantitativelydetermining the amount of spelter on galvanized wire, such as strippingthe coating in caustic soda solution; in a suitable hydrochloric acidsoluf,

tion; in a solution of hydrochloric` acid and antimony chloride, and ina lead acetate heavy coatingof spelter in order to solution. The coppersulfate test, although` not strictly. quantitative, is comparative whenused under known conditions of tempera-Y ture and strength, and being aquick test, and one which can be performed by any one after a littleexperience, has come to be the routine testing'medium for galvanizedwire coatings.

At .the present time there are only two (2)' methods in use wherebythesenecessary heavy zinc (spelter) coatings may be obtained by the hotprocess of galvanizing. The first method is to pass the wire very slowlyas it emerges from the galvanizing bath, through finely dividedcharcoal. By

such a process a smooth, thick coating may f be obtained. This method isused for making telephone wire. Tt has serious drawbacks, however, froman economic standpoint, because the wire must travel at a -very slowspeed, a very high grade zinc must be used, and, furthermore,A thecoated wire cannot be subjected to the action of wire-fence fabricatingmachines without having considerable of the zinc coating crack or flakeoff the iron base. The Second method is to cause 'the wire to travel atrelatively slow speeds, through a bath of molten spelter, the speeddepending on the gauge of wire, the thickness of coating. desired andvthe length of the molten spelter bath, and then wiping the wire bypassing it between suitable wipers. Tn other words, a wire will have aheavier galvanized coating,as measured by the copper sulfate test, thelonger it remains in the molten spelter. This latter process, too, hasits economic drawbacks, because of the slow speeds required, the longspelter pans necessary and g1ven time.v

5 coming into contact with the air.

consequently the lessening of the tonnage passing through a galvanizingunit in -,a

In the 4accompanying illustrated diagrammatically the usual or ordinarycontinuous galvanizing or coating apparatus, except that the annealingfuri ,nace is not placed as it is ordinarilybut which is placed adjacentthe coating bath,

and includes acid bath, flux bath, an-' nealing furnace, coating bathand heattreater. The annealing furnace is shown -in relation to thecoating bath so that wire may enter lthecoating bath from the annealingfurnace at a high temperature without In the illustration I show this bymeans of-a tube sealed from the air at both ends by being submergedAbelow the surface of the lead in the annealingfurnace and below thespelter or other metal of the coating bath. When the tube is heated allthe oxygen in the confined air is'` soon used up and both ends beingsealed no more air can enter so long as the heat is maintained.

I have discovered that if the material is subjected to an annealingtemperature and new, and results in producing a coated wire superior toany which can be produced by ordinary coating processes except in thecase of heavy wires where long Vspelter pans are utilized and whererelatively slow speeds are used.

I also realize that the annealing temperature will vary for differentcarbon contents,

orkinds of wire, or whether the annealing is to relieve the strain ofbench hardening that comes from the cold working of the wire, vorwhether from some other source, as I have stated in my companionapplication bearing Serial Number 541,561.

By annealingI `refer to softening and by heat-treatment I have reference-to `such treatment -as will produceV a physical or chemical change ofthey material undergoing treatment, such as I have disclosed incopending application bea-ring Serial lNumber 535,660. c

-F or example, I have taken 4a .bench hardened 0.12%- carbon No.12 gaugewire and passed it through a bath of molten lead drawing there is heatedto a temperature of about *12500- F.

for a period of about seven seconds and then without allowing theannealed wire to come.

into contact with air andl preferably while still in a heated condition,immersing the same inmolten spelter at a temperature of about 1200"F fora period of about three seconds and then passing 'the same through atube heated to` a temperature of about 1250'o F. I then have an annealedproduct which not only has a smooth even coating but a coating whichwill also stand approximately four or moreone minute immersions incopper sulfate.

It is Well known to those skillednthe art that an oxidized wire cannotbe suitably coated and it is for this reason that I do not permit theheated annealed wire to come into contact with the air beforeimmersingitin the coating bath. In ordinary processes it is necessary toremove this oxide by means of acid or some other `suitable nleansingmedium before subjecting the material to the coating bath. Andfurthermore I. have found that I get-an .improved bonding action betweenthe material and the coatingwhen I pass the material while in a heatedstate into the molten coating bath.

In my companion application bearing Serial Number 535,660 I havedisclosed the heat-treating of coated materials having an iron base,such for instance as coated wire, after the coating stepy and ofmaterial which is annealed in any well known manner prior to the coatingthereof. In this application I claimV the annealing of the material andthen coating it without allowing the same to come in contact with theair and -in a coating bath maintained at a'high temperature, say about1300 degrees F. I have found thatl with this process of coating I getvery good results with larger gauges of wires, such as No. 9, andcreatean effective bonding action between the coating and the basematerial; however, such bonding action 1s not 'as effective in the caseof smaller-'gauges `of wire, such as No. 14, be-v cause the small bodydoes not retain a suiicient amount oflieat to be as effective as thelarger bodies and therefore the subsequent heat-treatment is desirableand is employed for the purpose of accomplishing similar results as thatdisclosed by the use of the heat-treater in my companion application'bearing Serial Number 535,660;

y I do not wish to limit myself itc the tem'- peratures and periods oftime given above as I have clearly stated and shown in my copendingapplication bearing Serial No. 535,660 that times, speeds, and gauges ofwireinay be vutilized in a multitude of combinati'ons without departingfrom the spirit and scope of the invention.

What I claim is: l 1. The process of galvanizing wire, which insonniinto contact with air and While maintaining' the Wire at approximatelythe annealing temperature" subjecting the same to a coating bath.

2. The process of galvanizing Wire, which consists in continuously movig the Wire and during such movement subjecting the same, first-to anannealing action and then Without allowing the annealed Wire to comeinto f contact with air subjectingthe-same to va coating bath andfinally heat-treating said annealed and coated Wire.

3. The process of treating 11A-annealed materials having an iron basewhich consists in subjecting the same, first-to an annealing actionandthen Without allowing the annealed material to come into contact withair and While maintaining the material at approximately the annealingtemperature subjecting the same to a coating bath.

4. The process of treating un-annealed f in Witness whereof, l

materials having an iron base which' consists in subjecting the same,first-to an annealing action and then Without allowing the annealedmaterial to come into contact with air subjecting the same to a coatingvbath, and finally heat-treating said annealed and coated material.

5. The process of galvanizing Wire, whichv 'and during suchmovement'subjecting the same, firstt0 an annealing action and then whilemaintaining the Wire at approximately the annealing temperaturesubjecting said Wire to a coating bath.

6. The process of treating un-annealed materials having an iron basewhich consists, in subjecting the same, first-to an annealing action andthen While maintaining the material at approximately the annealingtemperature subjecting said material to a coating bath. f

have hereunto affixed my hand and seal this 4th day of Marcin 1922.,

Josnrjn L. HERMAN. '[L. 8.]

